The term "stent" is generally used to describe radially expandable endoluminal devices which are implanted within luminal anatomical passageways (e.g., blood vessels, gastrointestinal tract, genitourinary tract, endocrine ducts, etc. . . . ) of the body to, i.) maintain the patency or state of dilation of the passageway, ii.) reinforce the passageway, or iii.) anchor a tubular graft or other object within the passageway.
Typical cardiovascular applications of stents are to maintain dilation and patency of an occluded region of blood vessel, or to bridge a weakened or aneurysmic region of blood vessel. On the other hand, some typical non-vascular applications of such stents are for the treatment of constrictions or injuries to the gastrointestinal tract (e.g., esophagus), ducts of the biliary tree (e.g., common bile duct) or anatomical passageways of the genitourinary tract (e.g., ureter, urethra fallopian tube, etc.).
Transluminally implantable stents are initially disposed in a compact configuration of relatively small diameter, and are mounted upon or within a delivery catheter to facilitate insertion and transluminal advancement of the stent into the desired anatomical passageway. Thereafter, such stents are radially expanded to a larger operative diameter which is equal to or slightly larger than the diameter of the anatomical passageway in which the stent is to be implanted. When radially expanded to such operative diameter, the stent will typically become released or separated from the delivery catheter and anchored or frictionally engaged to the surrounding wall of the anatomical passageway.
Some stents have a pliable, continuous tubular covering, in which case they are typically referred to as a "stented graft" or "stent-graft."
In general, stents and stented grafts fall into two major categories--a) self-expanding and b) pressure-expandable. Those of the self-expanding variety may be formed of resilient or shape memory material (e.g., spring steel or nitinol.TM.) which is capable of self-expanding from its first (radially compact) diameter to its second (operative) diameter without the exertion of outwardly-directed force against the stent or stented graft. Examples of such self-expanding stents and stented grafts are set forth in U.S. Pat. Nos. 4,655,771 (Wallsten, et al.); 4,954,126 (Wallsten); 5,061,275 (Wallsten, et al.); 4,580,568 (Gianturco); 4,830,003 (Wolf, et al.); 5,035,706 (Gianturco, et al.); 5,330,400 (Song) and 5,354,308 (Simon, et al.) and Foreign Patent Publication Nos. WO94/12136; WO92/06734 and EPA183372. Those of the pressure-expandable (i.e., "passive expandable") variety may be formed of plastically deformable material (e.g., stainless steel) which is initially formed in its first (radially compact) diameter and remains stable in such first diameter until such time as outwardly directed pressure is exerted upon the stent or stented graft to cause it to undergo radial expansion and resultant plastic deformation to its second (operative) diameter. Examples of such pressure-expandable stents and stented grafts are set forth in U.S. Pat. Nos. 5,135,536 (Hillstead); 5,161,547 (Tower); 5,292,331 (Boneau); 5,304,200 (Spaulding); 4,733,665 (Palmaz); 5,282,823 (Schwartz, et al.); 4,776,337 (Palmaz); and 5,403,341 (Solar) and Foreign Patent Publication Nos. EPA480667; and WO95/08966.
In many applications, careful positioning and sound anchoring of the stent or stented graft is critical to the successful treatment of the underlying medical problem. In this regard, the delivery catheter which is utilized to insert and position the stent or stented graft may be an important aspect of the overall system. Various types of delivery catheters for stents and stented grafts have been previously known, including those described in U.S. Pat. Nos. 4,665,918 (Garza, et al.); 4,733,665 (Palmaz); 4,739,762 (Palmaz); 4,762,125 (Leiman, et al.); 4,776,337 (Palmaz); 4,838,269 (Robinson, et al.); 4,994,071 (MacGregor); 5,037,427 (Harada, et al.); 5,089,005 (Harada); 5,102,417 (Palmaz); 5,108,416 (Ryan, et al.); 5,141,498 (Christian); 5,181,920 (Mueller, et al.); 5,195,984 (Schatz); 5,201,901 (Harada, et al.); 5,269,763 (Boehmer, et al.); 5,275,622 (Lazarus, et al.); 5,290,295 (Querals, et al.); 5,306,294 (Winston, et al.); 5,318,588 (Horzewski, et al.); 5,344,426 (Lau, et al.); 5,350,363 (Goode, et al.); 5,360,401 (Turnland); 5,391,172 (Williams, et al.); 5,397,345 (Lazarus); 5,405,380 (Gianotti, et al.); 5,443,452 (Hart, et al.); 5,453,090 (Martinez, et al.); 5,456,284 (Ryan, et al.); and 5,456,694 (Marin, et al.) and Foreign Patent Publication Nos. EP-0308-815-A2; EP-0335-341-A1; EP-364-787-A; EP-0442-657-A2; EP-482976-A; EP-0505-686-A1; EP-0611-556-A1; EP-0638-290-A1; WO94/15549; WO95/01761; GB2196-857-A; DE3042-229; and DE3737-121-A.
None of the previously-known delivery catheter systems have been clearly optimal for all types of stents and stented grafts. Accordingly, there remains a need in the art for a design and development of improved delivery catheter systems for at least some types of stents and stented grafts.